From the Guidelines
Workup for Hyperglycemia
The workup for hyperglycemia involves a comprehensive evaluation to determine the underlying cause and severity of the condition.
- Initial laboratory tests include a fasting plasma glucose (FPG) level, hemoglobin A1c (HbA1c), and a complete metabolic panel to assess renal function and electrolyte balance 1.
- Medications such as metformin (500-1000 mg orally twice daily) or insulin glargine (10-20 units subcutaneously once daily) may be initiated to achieve glycemic control, with dose adjustments based on regular monitoring of FPG and HbA1c levels 1.
- Additionally, a urine analysis and screening for ketones may be performed to rule out diabetic ketoacidosis, particularly in patients with severe hyperglycemia (glucose >250 mg/dL) 1.
Glycemic Targets
- Inpatient glucose targets of 7.8 to 10 mmol/L (140 to 180 mg/dL) are recommended for most noncritical and critically ill patients 1.
- More stringent goals, such as 6.1 to 7.8 mmol/L (110 to 140 mg/dL), may be appropriate for selected patients, such as cardiac surgery patients or those with acute ischemic cardiac or neurologic events, if the targets can be achieved without significant hypoglycemia 1.
Insulin Therapy
- Insulin therapy should be initiated for the treatment of persistent hyperglycemia >180 mg/dL (10.0 mmol/L) and targeted to a glucose range of 140–180 mg/dL (7.8–10.0 mmol/L) for the majority of critically ill patients 1.
- Scheduled subcutaneous insulin injections should align with meals and bedtime or should be administered every 4 to 6 hours if no meals are consumed or continuous enteral or parenteral therapy is used 1.
From the Research
Appropriate Workup for Hyperglycemia
The workup for hyperglycemia involves several steps to determine the underlying cause and severity of the condition. The following are some key points to consider:
- Diagnosis of diabetes can be established using American Diabetes Association (ADA) criteria, which include a random plasma glucose ≥ 200 mg/dL (11.1 mmol/L) and symptoms of hyperglycemia 2
- Measurement of blood glycated proteins such as Hemoglobin A1c (HbA1c) and glycated albumin (GA) can provide information about glycemic control over a period of time 3
- HbA1c is one of the most important diagnostic factors for diabetes, but it may not be suitable for all diabetic patients, and GA can be a good alternative indicator of glycemic control 3
- In the emergency department, hyperglycemic patients without a history of diabetes can be evaluated using random plasma glucose levels, and treatment can be initiated based on the severity of hyperglycemia 2
Laboratory Tests
Some key laboratory tests used to evaluate hyperglycemia include:
- Fasting plasma glucose level (FPG)
- 2-h plasma glucose (2HP)
- Random plasma glucose
- HbA1c
- Glycated albumin (GA)
- High-performance liquid chromatography (HPLC), immunoassay, and electrophoresis are common laboratory methods used to measure glycated proteins 3
Management
Management of hyperglycemia involves:
- Insulin infusion protocols to control blood glucose levels in critically ill patients 4
- Conversion from insulin infusion to a subcutaneous insulin-delivery regimen in preparation for transfer from the cardiac care unit (CCU) setting 4
- Guidelines for management of diabetic ketoacidosis and hyperosmolar hyperglycemic states 4
- Activation of diabetes care team and their involvement in the multidisciplinary care of a patient in CCU with hyperglycemia and/or diabetes mellitus 4
Considerations
Some important considerations when evaluating and managing hyperglycemia include:
- Hyperglycemia in the inpatient setting can be non-specific, and patients with transient hyperglycemia may be incorrectly labeled as having diabetes, leading to unnecessary treatment and potential harm 5
- Clinicians should be cautious when responding to elevated random plasma glucose tests in the inpatient setting, and consider the diagnostic value of using random blood glucose to diagnose diabetes in this setting 5